Fixed problems with importing assets

ccm-cms/src/main/java/org/librecms/assets/AbstractAssetImExporter.java

@@ -21,10 +21,13 @@ package org.librecms.assets;
 import org.libreccm.imexport.AbstractEntityImExporter;
 import org.librecms.contentsection.Asset;
 import org.librecms.contentsection.AssetRepository;
+import org.librecms.contentsection.ItemAttachmentImExporter;
 
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 
+import javax.annotation.PostConstruct;
 import javax.inject.Inject;
 
 /**
@@ -38,6 +41,20 @@ public abstract class AbstractAssetImExporter<T extends Asset>
     @Inject
     private AssetRepository assetRepo;
 
+    @Inject
+    private ItemAttachmentImExporter itemAttachmentImExporter;
+    
+    @PostConstruct
+    @Override
+    protected final void init() {
+        // ItemAttachmentImExporter requires that all assets to be imported
+        itemAttachmentImExporter.addRequiredEntities(Set.of(getEntityClass()));
+        
+        initAssetImExporter();
+    }
+    
+    protected abstract void initAssetImExporter();
+    
     @Override
     protected Optional<T> findExistingEntity(final String uuid) {
         return assetRepo.findByUuidAndType(uuid, getEntityClass());

ccm-cms/src/main/java/org/librecms/assets/AbstractBinaryAssetImExporter.java

@@ -29,6 +29,13 @@ import java.util.Objects;
 public abstract class AbstractBinaryAssetImExporter<T extends BinaryAsset>
     extends AbstractAssetImExporter<T> {
 
+    @Override
+    protected final void initAssetImExporter() {
+        initBinaryAssetImExporter();
+    }
+
+    protected abstract void initBinaryAssetImExporter();
+
     @Override
     protected final void updateExistingAsset(
         final T existingAsset,
@@ -68,7 +75,7 @@ public abstract class AbstractBinaryAssetImExporter<T extends BinaryAsset>
         if (existingAsset.getSize() != importedAsset.getSize()) {
             existingAsset.setSize(importedAsset.getSize());
         }
-        
+
         updateExistingBinaryAsset(existingAsset, importedAsset);
     }
 

ccm-cms/src/main/java/org/librecms/assets/AbstractBookmarkImExporter.java

@@ -20,6 +20,7 @@ package org.librecms.assets;
 
 import java.util.Objects;
 
+
 /**
  *
  * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
@@ -28,6 +29,14 @@ import java.util.Objects;
 public abstract class AbstractBookmarkImExporter<T extends Bookmark>
     extends AbstractAssetImExporter<T> {
 
+    
+    @Override
+    protected final void initAssetImExporter() {
+        initBookmarkImExporter();
+    }
+    
+    protected abstract void initBookmarkImExporter();
+    
     @Override
     protected final void updateExistingAsset(
         final T existingAsset,

ccm-cms/src/main/java/org/librecms/assets/AbstractContactableEntityImExporter.java

@@ -21,8 +21,6 @@ package org.librecms.assets;
 import java.util.Objects;
 import java.util.Set;
 
-import javax.annotation.PostConstruct;
-
 /**
  *
  * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
@@ -31,12 +29,15 @@ import javax.annotation.PostConstruct;
 public abstract class AbstractContactableEntityImExporter<T extends ContactableEntity>
     extends AbstractAssetImExporter<T> {
 
-    @PostConstruct
     @Override
-    protected final void init() {
+    protected final void initAssetImExporter() {
         addRequiredEntities(Set.of(PostalAddress.class));
+
+        initContactableEntityImExporter();
     }
 
+    protected abstract void initContactableEntityImExporter();
+
     @Override
     protected final void updateExistingAsset(
         final T existingAsset,
@@ -48,24 +49,20 @@ public abstract class AbstractContactableEntityImExporter<T extends ContactableE
         )) {
             existingAsset.setContactEntries(importedAsset.getContactEntries());
         }
-        
+
         if (!Objects.equals(
             existingAsset.getPostalAddress(),
             importedAsset.getPostalAddress()
         )) {
             existingAsset.setPostalAddress(importedAsset.getPostalAddress());
         }
-        
+
         updateExistingContactable(existingAsset, importedAsset);
     }
-    
+
-    protected abstract void initContactableEntityImExporter();
-   
-    
     protected abstract void updateExistingContactable(
         final T existingContactable,
         final T importedContactable
     );
-   
 
 }

ccm-cms/src/main/java/org/librecms/assets/AudioAssetImExporter.java

@@ -31,7 +31,8 @@ import javax.enterprise.context.RequestScoped;
  */
 @RequestScoped
 @Processes(AudioAsset.class)
-public class AudioAssetImExporter extends AbstractBinaryAssetImExporter<AudioAsset> {
+public class AudioAssetImExporter 
+    extends AbstractBinaryAssetImExporter<AudioAsset> {
 
     @Override
     public Class<AudioAsset> getEntityClass() {
@@ -39,7 +40,7 @@ public class AudioAssetImExporter extends AbstractBinaryAssetImExporter<AudioAss
     }
 
     @Override
-    protected void init() {
+    protected void initBinaryAssetImExporter() {
         addRequiredEntities(Set.of(LegalMetadata.class));
     }
 

ccm-cms/src/main/java/org/librecms/assets/BookmarkImExporter.java

@@ -37,7 +37,7 @@ public class BookmarkImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initBookmarkImExporter() {
         // Nothing
     }
 

ccm-cms/src/main/java/org/librecms/assets/ExternalAudioAssetImExporter.java

@@ -40,7 +40,7 @@ public class ExternalAudioAssetImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initBookmarkImExporter() {
         addRequiredEntities(Set.of(LegalMetadata.class));
     }
 

ccm-cms/src/main/java/org/librecms/assets/ExternalVideoAssetImExporter.java

@@ -40,7 +40,7 @@ public class ExternalVideoAssetImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initBookmarkImExporter() {
         addRequiredEntities(Set.of(LegalMetadata.class));
     }
 

ccm-cms/src/main/java/org/librecms/assets/FileAssetImExporter.java

@@ -31,7 +31,7 @@ public class FileAssetImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initBinaryAssetImExporter() {
         // Nothing
     }
 

ccm-cms/src/main/java/org/librecms/assets/ImageImExporter.java

@@ -39,7 +39,7 @@ public class ImageImExporter extends AbstractBinaryAssetImExporter<Image> {
     }
 
     @Override
-    protected void init() {
+    protected void initBinaryAssetImExporter() {
         addRequiredEntities(Set.of(LegalMetadata.class));
     }
 

ccm-cms/src/main/java/org/librecms/assets/LegalMetadataImExporter.java

@@ -39,7 +39,7 @@ public class LegalMetadataImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initAssetImExporter() {
         // Nothing
     }
 

ccm-cms/src/main/java/org/librecms/assets/PostalAddressImExporter.java

@@ -33,7 +33,7 @@ public class PostalAddressImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initAssetImExporter() {
         // Nothing
     }
 

ccm-cms/src/main/java/org/librecms/assets/RelatedLinkImExporter.java

@@ -39,7 +39,7 @@ public class RelatedLinkImExporter extends AbstractAssetImExporter<RelatedLink>
     }
 
     @Override
-    protected void init() {
+    protected void initAssetImExporter() {
         addRequiredEntities(Set.of(Bookmark.class));
     }
 

ccm-cms/src/main/java/org/librecms/assets/SideNoteImExporter.java

@@ -38,7 +38,7 @@ public class SideNoteImExporter extends AbstractAssetImExporter<SideNote> {
     }
 
     @Override
-    protected void init() {
+    protected void initAssetImExporter() {
         // Nothing
     }
 

ccm-cms/src/main/java/org/librecms/assets/VideoAssetImExporter.java

@@ -40,7 +40,7 @@ public class VideoAssetImExporter
     }
 
     @Override
-    protected void init() {
+    protected void initBinaryAssetImExporter() {
         addRequiredEntities(
             Set.of(LegalMetadata.class)
         );

ccm-cms/src/main/java/org/librecms/contentsection/AbstractContentItemImExporter.java

@@ -35,7 +35,6 @@ import java.util.Set;
 import javax.annotation.PostConstruct;
 import javax.enterprise.inject.Any;
 import javax.inject.Inject;
-import javax.transaction.Transactional;
 
 /**
  *
@@ -45,6 +44,9 @@ import javax.transaction.Transactional;
 public abstract class AbstractContentItemImExporter<T extends ContentItem>
     extends AbstractEntityImExporter<T> {
 
+    @Inject
+    private AttachmentListImExporter attachmentListImExporter;
+    
     @Inject
     private ContentItemRepository itemRepository;
 
@@ -80,6 +82,9 @@ public abstract class AbstractContentItemImExporter<T extends ContentItem>
         // get the target item.
         relatedLinkImExporter.addRequiredEntities(Set.of(getEntityClass()));
 
+        //AttachmentList import requiresw all content items to be imported
+        attachmentListImExporter.addRequiredEntities(Set.of(getEntityClass()));
+        
         initContentItemImExporter();
     }
 

ccm-cms/src/main/java/org/librecms/contentsection/AttachmentList.java

@@ -18,8 +18,10 @@
  */
 package org.librecms.contentsection;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import org.hibernate.envers.Audited;
 import org.libreccm.core.Identifiable;
+import org.libreccm.imexport.Exportable;
 import org.libreccm.l10n.LocalizedString;
 import org.libreccm.security.RecursivePermissions;
 import org.librecms.contentsection.privileges.AssetPrivileges;
@@ -48,7 +50,6 @@ import javax.persistence.Table;
 
 import static org.librecms.CmsConstants.DB_SCHEMA;
 
-
 /**
  * A list of assets attached a {@link ContentItem}. Each {@link ContentItem} may
  * have multiple lists of attachments. Each list can be identified by name which
@@ -64,22 +65,23 @@ import static org.librecms.CmsConstants.DB_SCHEMA;
     @NamedQuery(
         name = "AttachmentList.findById",
         query = "SELECT l FROM AttachmentList l WHERE l.listId = :listId"
-    )
+    ),
-    ,
+    @NamedQuery(
+        name = "AttachmentList.findByUuid",
+        query = "SELECT l FROM AttachmentList l WHERE l.uuid = :uuid"
+    ),
     @NamedQuery(
         name = "AttachmentList.findForItemAndId",
         query = "SELECT l FROM AttachmentList l "
-            + "WHERE l.listId = :listId "
+                    + "WHERE l.listId = :listId "
-            + "AND l.item = :item"
+                    + "AND l.item = :item"
-    )
+    ),
-    ,
     @NamedQuery(
         name = "AttachmentList.findForItemAndUuid",
         query = "SELECT l FROM AttachmentList l "
-            + "WHERE l.uuid = :uuid "
+                    + "WHERE l.uuid = :uuid "
-            + "AND l.item = :item"
+                    + "AND l.item = :item"
-    )
+    ),
-    ,
     @NamedQuery(
         name = "AttachmentList.findForItemAndName",
         query = "SELECT l FROM AttachmentList l "
@@ -89,6 +91,7 @@ import static org.librecms.CmsConstants.DB_SCHEMA;
 })
 public class AttachmentList implements Comparable<AttachmentList>,
                                        Identifiable,
+                                       Exportable,
                                        Serializable {
 
     private static final long serialVersionUID = -7931234562247075541L;
@@ -122,7 +125,7 @@ public class AttachmentList implements Comparable<AttachmentList>,
 
     /**
      * A listOrder index for ordering multiple attachment lists with the same
- {@link #name}.
+     * {@link #name}.
      */
     @Column(name = "LIST_ORDER")
     private long listOrder;
@@ -133,11 +136,12 @@ public class AttachmentList implements Comparable<AttachmentList>,
     @Embedded
     @AssociationOverride(
         name = "values",
-        joinTable = @JoinTable(name = "ATTACHMENT_LIST_CAPTIONS",
+        joinTable = @JoinTable(
-                               schema = DB_SCHEMA,
+            name = "ATTACHMENT_LIST_CAPTIONS",
-                               joinColumns = {
+            schema = DB_SCHEMA,
-                                   @JoinColumn(name = "LIST_ID")
+            joinColumns = {
-                               }
+                @JoinColumn(name = "LIST_ID")
+            }
         )
     )
     private LocalizedString title;
@@ -148,18 +152,26 @@ public class AttachmentList implements Comparable<AttachmentList>,
     @Embedded
     @AssociationOverride(
         name = "values",
-        joinTable = @JoinTable(name = "ATTACHMENT_LIST_DESCRIPTIONS",
+        joinTable = @JoinTable(
-                               schema = DB_SCHEMA,
+            name = "ATTACHMENT_LIST_DESCRIPTIONS",
-                               joinColumns = {
+            schema = DB_SCHEMA,
-                                   @JoinColumn(name = "LIST_ID")
+            joinColumns = {
-                               }))
+                @JoinColumn(name = "LIST_ID")
+            }
+        )
+    )
     private LocalizedString description;
 
     @OneToMany(mappedBy = "attachmentList")
     @OrderBy("sortKey ASC")
-    @RecursivePermissions(privileges = {AssetPrivileges.EDIT, 
+    @RecursivePermissions(
-                                        AssetPrivileges.DELETE, 
+        privileges = {
-                                        AssetPrivileges.VIEW})
+            AssetPrivileges.EDIT,
+            AssetPrivileges.DELETE,
+            AssetPrivileges.VIEW
+        }
+    )
+    @JsonIgnore
     private List<ItemAttachment<?>> attachments;
 
     public AttachmentList() {
@@ -167,7 +179,7 @@ public class AttachmentList implements Comparable<AttachmentList>,
         description = new LocalizedString();
         attachments = new ArrayList<>();
     }
-    
+
     public long getListId() {
         return listId;
     }
@@ -192,7 +204,7 @@ public class AttachmentList implements Comparable<AttachmentList>,
     protected void setItem(final ContentItem item) {
         this.item = item;
     }
-    
+
     public String getName() {
         return name;
     }

ccm-cms/src/main/java/org/librecms/contentsection/AttachmentListImExporter.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2023 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.librecms.contentsection;
+
+import org.libreccm.imexport.AbstractEntityImExporter;
+import org.libreccm.imexport.Processes;
+
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+
+import javax.enterprise.context.RequestScoped;
+import javax.inject.Inject;
+
+/**
+ *
+ * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
+ */
+@RequestScoped
+@Processes(AttachmentList.class)
+public class AttachmentListImExporter
+    extends AbstractEntityImExporter<AttachmentList> {
+
+    @Inject
+    private AttachmentListRepository attachmentListRepo;
+
+    @Override
+    public Class<AttachmentList> getEntityClass() {
+        return AttachmentList.class;
+    }
+
+    @Override
+    protected void init() {
+        addRequiredEntities(Set.of(ItemAttachment.class));
+    }
+
+    @Override
+    protected Optional<AttachmentList> findExistingEntity(final String uuid) {
+        return attachmentListRepo.findByUuid(uuid);
+    }
+
+    @Override
+    protected void saveImportedEntity(final AttachmentList entity) {
+        attachmentListRepo.save(entity);
+    }
+
+    @Override
+    protected void updateExistingEntity(
+        final AttachmentList existingEntity,
+        final AttachmentList withImportedEntity
+    ) {
+        if (!Objects.equals(
+            existingEntity.getName(),
+            withImportedEntity.getName()
+        )) {
+            existingEntity.setName(withImportedEntity.getName());
+        }
+        
+        if (existingEntity.getListOrder() != withImportedEntity.getListOrder()) {
+            existingEntity.setListOrder(withImportedEntity.getListOrder());
+        }
+        
+        if (!Objects.equals(
+            existingEntity.getTitle(),
+            withImportedEntity.getTitle()
+        )) {
+            syncLocalizedStrings(
+                withImportedEntity.getTitle(), 
+                existingEntity.getTitle()
+            );
+        }
+        
+        if (!Objects.equals(
+            existingEntity.getDescription(),
+            withImportedEntity.getDescription()
+        )) {
+            syncLocalizedStrings(
+                withImportedEntity.getDescription(), 
+                existingEntity.getDescription()
+            );
+        }
+        
+        attachmentListRepo.save(existingEntity);
+    }
+
+    @Override
+    protected AttachmentList reloadEntity(AttachmentList entity) {
+        return attachmentListRepo
+            .findById(Objects.requireNonNull(entity).getListId())
+            .orElseThrow(
+                () -> new IllegalArgumentException(
+                    String.format(
+                        "AttachmentList entity %s does not exist in "
+                            + "the database.,",
+                        Objects.toString(entity)
+                    )
+                )
+            );
+    }
+
+}

ccm-cms/src/main/java/org/librecms/contentsection/AttachmentListRepository.java

@@ -36,6 +36,22 @@ public class AttachmentListRepository
 
     private static final long serialVersionUID = 1L;
 
+    public Optional<AttachmentList> findByUuid(final String uuid) {
+        try {
+            return Optional.of(
+                getEntityManager()
+                    .createNamedQuery(
+                        "AttachmentList.findByUuid",
+                        AttachmentList.class
+                    )
+                    .setParameter("uuid", uuid)
+                    .getSingleResult()
+            );
+        } catch (NoResultException ex) {
+            return Optional.empty();
+        }
+    }
+
     /**
      * Retrieves an attachment list for a specific item by the ID of the list.
      *

ccm-cms/src/main/java/org/librecms/contentsection/FolderImExporter.java

@@ -65,6 +65,11 @@ public class FolderImExporter extends AbstractEntityImExporter<Folder> {
         return Folder.class;
     }
 
+    @Override
+    protected Optional<Folder> findExistingEntity(final String uuid) {
+        return folderRepo.findByUuid(uuid);
+    }
+
     @Override
     protected void saveImportedEntity(final Folder entity) {
         folderRepo.save(entity);
@@ -163,7 +168,7 @@ public class FolderImExporter extends AbstractEntityImExporter<Folder> {
         if (existingEntity.isVisible() != withImportedEntity.isVisible()) {
             existingEntity.setVisible(withImportedEntity.isVisible());
         }
-        
+
         folderRepo.save(existingEntity);
     }
 
@@ -181,9 +186,4 @@ public class FolderImExporter extends AbstractEntityImExporter<Folder> {
             );
     }
 
-    @Override
-    protected Optional<Folder> findExistingEntity(String uuid) {
-        throw new UnsupportedOperationException("Not supported yet."); // Generated from nbfs://nbhost/SystemFileSystem/Templates/Classes/Code/GeneratedMethodBody
-    }
-
 }

ccm-cms/src/main/java/org/librecms/contentsection/ItemAttachment.java

@@ -20,6 +20,7 @@ package org.librecms.contentsection;
 
 import org.hibernate.envers.Audited;
 import org.libreccm.core.Identifiable;
+import org.libreccm.imexport.Exportable;
 
 import java.io.Serializable;
 import java.util.Objects;
@@ -52,14 +53,16 @@ import static org.librecms.CmsConstants.*;
     @NamedQuery(
         name = "ItemAttachment.findById",
         query = "SELECT i FROM ItemAttachment i "
-                    + "WHERE i.attachmentId = :attachmentId")
+                    + "WHERE i.attachmentId = :attachmentId"),
-    ,
+    @NamedQuery(
+        name = "ItemAttachment.findByUuid",
+        query = "SELECT i FROM ItemAttachment i WHERE i.uuid = :uuid"
+    ),
     @NamedQuery(
         name = "ItemAttachment.countByAssetIdAndList",
         query = "SELECT COUNT(i) FROM ItemAttachment i "
                     + "WHERE i.asset = :asset "
-                    + "AND i.attachmentList = :attachmentList")
+                    + "AND i.attachmentList = :attachmentList"),
-    ,
     @NamedQuery(
         name = "ItemAttachment.findByAssetByAndList",
         query = "SELECT i FROM ItemAttachment i "
@@ -70,6 +73,7 @@ import static org.librecms.CmsConstants.*;
 public class ItemAttachment<T extends Asset>
     implements Comparable<ItemAttachment<?>>,
                Identifiable,
+               Exportable,
                Serializable {
 
     private static final long serialVersionUID = -9005379413315191984L;
@@ -99,8 +103,10 @@ public class ItemAttachment<T extends Asset>
      * The {@link Asset} which is linked by this attachment to the
      * {@link #attachmentList}.
      */
-    @ManyToOne(targetEntity = Asset.class,
+    @ManyToOne(
-               cascade = {CascadeType.PERSIST})
+        targetEntity = Asset.class,
+        cascade = {CascadeType.PERSIST}
+    )
     @JoinColumn(name = "ASSET_ID")
     private T asset;
 

ccm-cms/src/main/java/org/librecms/contentsection/ItemAttachmentImExporter.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2023 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.librecms.contentsection;
+
+import org.libreccm.imexport.AbstractEntityImExporter;
+import org.libreccm.imexport.Processes;
+
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+
+import javax.enterprise.context.RequestScoped;
+import javax.inject.Inject;
+
+/**
+ *
+ * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
+ */
+@RequestScoped
+@Processes(ItemAttachment.class)
+@SuppressWarnings("rawtypes")
+public class ItemAttachmentImExporter
+    extends AbstractEntityImExporter<ItemAttachment> {
+
+    @Inject
+    private ItemAttachmentRepository itemAttachmentRepo;
+
+    @Override
+    public Class<ItemAttachment> getEntityClass() {
+        return ItemAttachment.class;
+    }
+
+    @Override
+    protected void init() {
+        addRequiredEntities(Set.of(AttachmentList.class));
+    }
+
+    @Override
+    protected Optional<ItemAttachment> findExistingEntity(final String uuid) {
+        return itemAttachmentRepo.findByUuid(uuid);
+    }
+
+    @Override
+    protected void saveImportedEntity(final ItemAttachment entity) {
+        itemAttachmentRepo.save(entity);
+    }
+
+    @Override
+    protected void updateExistingEntity(
+        ItemAttachment existingEntity,
+        ItemAttachment withImportedEntity
+    ) {
+        if (existingEntity.getSortKey() != withImportedEntity.getSortKey()) {
+            existingEntity.setSortKey(withImportedEntity.getSortKey());
+        }
+        
+        itemAttachmentRepo.save(existingEntity);
+    }
+
+    @Override
+    protected ItemAttachment reloadEntity(ItemAttachment entity) {
+        return itemAttachmentRepo
+            .findById(Objects.requireNonNull(entity).getAttachmentId())
+            .orElseThrow(
+                () -> new IllegalArgumentException(
+                    String.format(
+                        String.format(
+                            "ItemAttachment %s does not exist in the database.",
+                            Objects.toString(entity)
+                        )
+                    )
+                )
+            );
+    }
+
+}

ccm-cms/src/main/java/org/librecms/contentsection/ItemAttachmentRepository.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2023 LibreCCM Foundation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+package org.librecms.contentsection;
+
+import org.libreccm.core.AbstractEntityRepository;
+
+import java.util.Optional;
+import java.util.UUID;
+
+import javax.enterprise.context.RequestScoped;
+import javax.persistence.NoResultException;
+
+/**
+ *
+ * @author <a href="mailto:jens.pelzetter@googlemail.com">Jens Pelzetter</a>
+ */
+@RequestScoped
+@SuppressWarnings("rawtypes")
+public class ItemAttachmentRepository
+    extends AbstractEntityRepository<Long, ItemAttachment> {
+
+    @Override
+    public Class<ItemAttachment> getEntityClass() {
+        return ItemAttachment.class;
+    }
+
+    @Override
+    public String getIdAttributeName() {
+        return "attachmentId";
+    }
+
+    @Override
+    public Long getIdOfEntity(final ItemAttachment entity) {
+        return entity.getAttachmentId();
+    }
+
+    @Override
+    public boolean isNew(final ItemAttachment entity) {
+        return entity.getAttachmentId() == 0;
+    }
+
+    @Override
+    protected void initNewEntity(final ItemAttachment entity) {
+        entity.setUuid(UUID.randomUUID().toString());
+    }
+
+    public Optional<ItemAttachment> findByUuid(final String uuid) {
+        try {
+            return Optional.of(
+                getEntityManager()
+                    .createNamedQuery(
+                        "ItemAttachment.findByUuid",
+                        ItemAttachment.class
+                    )
+                    .setParameter("uuid", uuid)
+                    .getSingleResult()
+            );
+        } catch (NoResultException ex) {
+            return Optional.empty();
+        }
+    }
+
+}